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    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        section div:nth-child(1) {
            background-color: red;
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        section div:nth-of-type(1) {
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<body>
    <section>
        <p>光头强</p>
        <div>熊大</div>
        <div>熊二</div>
    </section>
</body>

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